Nonwoven fabrics are generally understood as fabric-like materials, made from fibers that are bonded together by chemical, mechanical, heat or even solvent treatment. They may be in the form of sheet or web structures. They are not made by weaving or knitting and do not require conversion of the fibers to yarn. Nonwoven fabrics therefore seek to provide the appearance, texture and strength of a woven fabric and can result in a variety of useful products for apparel, home furnishings, and a variety of consumer goods.
The spunbond process generally makes use of a polymer feed, a metering pump, a die assembly, a filament spinning, a drawing and deposition system, a collecting belt, a bonding zone and a winding. See, e.g., “A Review Of Spun Bond Process”, H. Lim, Journal of Textile Apparel, Technology and Management, Vol. 6, Issue 3, Spring 2010.
One particular type of spunbond non-woven is sourced from polyester type polymers. Polyester spunbond can amount to a manufactured sheet of randomly oriented polyester filaments bonded by calendaring, needling, chemically with a binder, or a combination of these methods. In general, relatively small diameter filaments can be formed by extruding one or more molten polyester fibers from a spinneret. The extruded fibers are cooled while being drawn to form spunbond fibers or continuous filaments, which are deposited or laid onto a forming surface in a random manner to form a loosely entangled web. This web is then subjected to a bonding process.